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Thread: Gear questions

  1. #1
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    Default Gear questions

    Automotive gearboxes usually use helical gears with syncro's. Can a quality spur gear be machined using home shop equipment that will hold up under racing conditions (high horsepower (600hp))?

    What kind of gears are used by motorcycles?

  2. #2
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    Ultra precision gears hobbed from billets of unobtainium lapped to ultrafine finish with hand wrapped cigarillo ashes from old Mexico no doubt....




    Seriously, though at 600 HP, there is either serious torque, or ultrahigh speeds, or both

  3. #3
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    It's not just the machining. More important is the Heat Treating. Just heating with a torch, quenching in oil or water and drawing it roughly back ain't gonna cut it
    The optimist says the glass is half full, the pessimist says it's half empty. The paranoid in me says somebody put a hole in it.

    Remember pessimists are at heart opptomists. They know things can and will get worse.

  4. #4
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    Yeah, what the Doc said.... It seems highly unlikely that materials and heat treating methods available in the home shop would stand up to that kind of service....

  5. #5
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    Quote Originally Posted by Spin Doctor
    It's not just the machining. More important is the Heat Treating. Just heating with a torch, quenching in oil or water and drawing it roughly back ain't gonna cut it
    What if the heat treatment is done by a professional heat treat shop?

  6. #6
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    Quote Originally Posted by Neil Jones
    What if the heat treatment is done by a professional heat treat shop?
    That would help but how you going th grind it after . The bore and the teeth profile plus the face width. then what you going th check it with. Think,Think.

  7. #7
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    That is right. Some amount can be done with pin gages but hardened stuff will need grinding, if it is to be accurate. While many HSMs have some sort of grinding machines they will not have involute dressers and as I understand those are not something you beat up from bits and pieces (not that that stops us)

    Pre-hard might cut it but I think not.

  8. #8
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    Watching Lane getting that gear we made up for the South Bend gear box (which is a loooong way from what youre talking about) made me appreciate - just a small portion - of what can be involved in gear cutting,- at least in a home shop situation. Even with Lanes years of experience it still wasnt an ideal match for the original...
    If everything seems to be going well, you have obviously overlooked something........

  9. #9
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    Years ago I came across a site run by some unlimited air race enthusiasts where there was an extensive discussion of their efforts to change reduction gear ratios in RR Merlin and Allison V12 engines. They had started out making their own gears (all helical) and had given up after some expensive failures in ground testing. Admittedly, they were working at higher horsepowers, but the problems are the same. In the end, it's cheaper to pay the pros in some cases.

    Joe
    "I am not academically qualified. I am what I call QBE - thatís my degree - Qualified By Experience."

    Rupert Neve, Audio Technology Magazine Issue 1, March 1998

  10. #10
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    Even the "Pros" are less than 100%. A few years back I was dealing with a manufacturer who wanted a coil and sensor inside a differential. The specifications called for the electronics to survive in gear lube that could be lousy with metal slivers and such. Seems that the gears generated a lot of such material in the first 3K miles or so while "wearing in".

    Same thing with another program dealing with automatic transmissions.
    Weston Bye - Author, The Mechatronist column, Digital Machinist magazine
    ~Practitioner of the Electromechanical Arts~

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